```python
import pandas as pd
import altair as alt
from vega_datasets import data
locations_table = pd.read_csv(r"https://raw.githubusercontent.com/SwanseaU-TTW/csc337_coursework1/master/pleiades-locations-latest.csv")
pd.set_option('display.max_columns', None)
alt.data_transformers.disable_max_rows()
locations_table.head()
countries = alt.topo_feature(data.world_110m.url, 'countries')
selector = alt.selection_single(empty='all', fields=['featureType'])
colours_condition = alt.condition(selector,'featureType:N',alt.value('#666666'))
# Used world cropping map of World inspired from https://stackoverflow.com/questions/61135952/vega-lite-altair-how-to-center-or-crop-a-map-of-europe
background = alt.Chart(countries).mark_geoshape(
fill='#666666',
stroke='white'
).project(
type= 'mercator',
scale= 155, # Magnify
center= [50,27], # [lon, lat]
).properties(
title='World (Mercator)',
)
binned_heatmap = alt.Chart(locations_table).mark_rect(
fillOpacity=0.5
).encode(
alt.X('reprLong:Q', bin=alt.Bin(maxbins=60)),
alt.Y('reprLat:Q', bin=alt.Bin(maxbins=60)),
alt.Color('count(featureType):Q', scale=alt.Scale(scheme='greenblue')),
).properties(
title='World (Mercator)',
)
background + binned_heatmap
```